As the Supreme Court prepares to hear two momentous cases on same-sex marriage this week, opposition is evaporating. From National Football League players to Karl Rove, who said he could imagine the next GOP presidential nominee endorsing same-sex marriage, everyone seems to be coming out of the closet in favor of gays and lesbians securing the right to marry. Missouri Sen. Claire McCaskill, a Democrat in a perilously swing state, is but the latest.

The editorial writers warn ominously that if Justice Anthony Kennedy doesn’t leave things to the voters in places like Alabama and North Carolina, he will “incite another Forty Years War,” as the Roe v. Wade decision did on abortion. “A same-sex marriage ukase would achieve that rare thing, harming advocates and opponents and everyone else in between,” they declare.

David Boies, co-counsel with former Bush Solicitor General Ted Olson, who is asking for a Prop. 8 ruling that declares same-sex marriage a constitutional right, answered that the relevant political precedent is not Roe, but Loving v. Virginia. Boies said told us last week that there was “not a ripple” of opposition from states that still banned interracial marriage in 1967 when the court ruled such bans unconstitutional.

If the court rules against same-sex marriage, it remains to be seen whether conservative states mount a counter-rebellion in the face of rising GOP defections. What is clear now is that a ruling to uphold DOMA and Prop. 8 would only delay the inevitable.

California Attorney General Kamala Harris is in Washington for the arguments, having refused to defend Prop. 8. San Francisco city attorney Dennis Herrera and his legal team, partners with Boies and Olson, are also here preparing for oral arguments Tuesday. San Francisco, a co-plaintiff in the Prop. 8 case, from the outset defended former Mayor Gavin Newsom’s 2004 decision to issue marriage licenses to gay and lesbian couples, later invalidated by the California Supreme Court, which said Newsom lacked legal authority.

Spokesman Matt Dorsey called Tuesday the culmination of a “nine-year odyssey” that has seen a shift in cultural attitudes that no one could have imagined when the city filed suite in 2004 to launch “the first government challenge to anti-gay marriage laws in U.S. history.”